I run this WP CLI command to finish the setup, it is idempotent,
which means that it doesn’t change an existing finished WordPress setup.
wp @production core install --url=<the-url> --title="<the-title>" --admin_user=<the-user> --admin_password="<the-password>" --admin_email=<the-email>
Edit: WP CLI can also be used for activating plugins + theme, installling languages packs and updating them - ideal as install hook.
Edit: Related thread: Install & update WordPress languages with WP-CLI